Percentage of observations where the VFR minimums for ceiling and visibility are met: visibility of 5 mi or more and a ceiling of 3,000 ft or more. Only observations between sunrise and sunset are taken into account.
Marginal VFR conditions (%)
Month
Average
2024
2023
2022
2021
2020
January
94.6
98
95
91
93
98
February
94.6
86
92
89
95
100
March
93.3
96
99
95
97
83
April
90.5
99
87
87
85
May
92.5
86
92
94
98
June
95.3
96
100
97
95
July
89.4
83
89
89
93
August
89.8
90
94
95
87
September
95.7
94
94
96
100
October
93.1
92
93
88
93
November
90.1
85
98
96
87
December
86.0
95
63
91
90
Average
92.3
93.6
92.0
91.4
92.7
92.0
Marginal VFR conditions or better during daylight period
Percentage of observations where the MVFR minimums for ceiling and visibility are met: visibility of 3⅛ mi or more and a ceiling of 1,000 ft or more. Only observations between sunrise and sunset are taken into account.
Maximum temperatures (°C)
Month
Average
2024
2023
2022
2021
2020
January
-22.4
-18
-26
-21
-15
-27
February
-25.0
-24
-26
-27
-19
-29
March
-18.3
-15
-13
-19
-19
-19
April
-10.7
-8
-11
-6
-9
May
-2.9
-2
-3
1
-1
June
5.5
4
6
6
5
July
10.2
9
10
10
12
August
10.0
11
10
10
11
September
4.7
3
7
4
5
October
-1.0
-2
0
1
0
November
-7.0
-4
-11
-7
-8
December
-12.2
-12
-7
-12
-10
Average
-7.0
-19.7
-6.0
-6.7
-4.3
-6.2
Average highest temperature per day
The maximum temperature is typically observed some hours after noon.